Multi-layered shingle and method of making same

ABSTRACT

A multi-layered shingle adapted to be positioned with other similar shingles in an overlapping arrangement on a roof to yield a simulated wooden shake roof covering comprising a headlap portion and a butt portion. The butt portion comprises a series of multi-layered tabs. All the tabs have the same number of layers and each multi-layered tab (a) is separated from the next adjacent multi-layered tab or tabs by a space or spaces, respectively, and (b) comprises an uppermost layer and at least two layers underlying the uppermost layer. Each underlying layer is laminated to the layer above it to form a multi-layered laminated composite. The laminated composite is integral with the headlap portion and the top surface of the uppermost layer of each tab is coplanar with the top surface of the headlap portion. The invention also includes an apparatus and a process for the continuous manufacture of the shingles of the invention.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation application of U.S. application Ser. No.09/994,393 filed Nov. 26, 2001 now U.S. Pat. No. 6,679,020, which inturn is a divisional of U.S. application Ser. No. 09/303,840 filed May3, 1999, now U.S. Pat. No. 6,355,132.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a method for making multi-layered shingles,and to roofing shingles made thereby. The shingles are uniquelythickened to enhance the appearance of a roof.

2. Description of the Prior Art

There have been many approaches by the roofing industry to the task ofcovering a roof deck with shingles which are both protective andaesthetically pleasing. Whatever their appearance, suitable shingleshave been made sufficiently durable and weatherproof for prolongedprotection of the roof. The shingles' visual appeal has been attained invarious ways, such as by providing particular butt edge contours andsurface treatments which function to simulate more traditional, and inmost cases more expensive, forms of roof coverings, including thatch,wooden shakes, slates, and even tiles of various forms.

Simulation of such more traditional roof coverings is afforded byasphalt shingles of the laminated type. These shingles provide depth orits appearance on the roof, thus more or less giving the look of thewood or other natural appearing shingles. U.S. Pat. No. 3,921,358provides an example of such composite shingles. After describing thefutile attempts in the past to achieve the irregular, bulky, butt edgeprofile and surface contour characteristic of wood roofing shingles,this patent presents an improved composite shingle comprising arectangular sheet having a headlap portion and a butt portion. The buttportion is divided into a series of spaced apart tabs and a strip issecured to the sheet in a position underlying the tabs and filling thespaces therebetween. While the resultant bilaminate structure suggestssomewhat the substantial and imposing architectural appearance of themore expensive roofing materials, such as wood shingles, the structurestill diverges considerably in appearance from them.

For many years roofing manufacturers have offered a variety oftwo-layered shingles of the type disclosed in U.S. Pat. No. 3,921,358 inthe attempt to present a thicker and more attractive appearance. Astructure markedly different from these prior art bilaminate shingles isshown in U.S. Pat. No. 4,869,942. This structure, which has an exposedbutt portion three layers in depth, with tabs two layers in depth, andan additional strip under the cut-outs, gives the shingle an appearancethat goes well beyond the bilaminates in simulating wood and tileshingles.

Although the asphalt composite shingles have significant cost, servicelife and non-flammability advantages over wood shingles, the latter typeare still seen by many to be a much more desirable roofing material foraesthetic purposes. A key reason for wood shingles' continuing aestheticappeal stems from their greater thickness relative to the compositeshingles, in spite of the many efforts in the past to simulate thisthickness. Accordingly, it would be most beneficial to find ways toenhance the appearance of depth in the composite shingles withoutsacrificing these shingles' advantageous features.

OBJECT OF THE INVENTION

It is therefore an object of the invention to provide an asphalt shinglethat simulates very closely the thickness of wood or other traditionalroof coverings, and also possesses those attributes desired in roofcoverings, including waterproofness, durability and fire-resistance.

It is a further object of the invention to enhance the appearance of alaminated shingle through the use of multiple layers of the butt portionof the shingle.

It is yet another object of the invention to provide a simple, efficientand economical manufacturing process for the continuous production of alaminated shingle from a single indefinitely long roofing sheet.

SUMMARY OF THE INVENTION

The foregoing and other objects of the invention have been achieved by aroof shingle which is multi-layered for enhancement of the shingle'svisual appeal and thickness. The composite shingle comprises a headlapportion and a butt portion having three or more layers. The headlapportion may also be multi-layered, comprising two or more layers. Thebutt portion is divided into a series of spaced apart tabs. The spacingbetween the tabs significantly exceeds that of the slots which have beenformed over the years in the manufacture of multi-layered shingles, suchas those disclosed in U.S. Pat. Nos. 5,209,802 and 5,426,902. Suchnarrow openings, which are typically less than one inch, e.g., about ¼to ⅝ inch, do not provide the openly spaced and particularly deep wellsof a roof surfaced by the shingles of the present invention. The spacingbetween the tabs of the inventive shingles is greater than 1 inch,preferably greater than 2 inches.

The multi-layered shingle is of the laminated type. The butt portion ofthis shingle composite is made of at least three laminae, and may havefour, five or more laminae. The laminae are preferably constructed offelted material comprising organic or inorganic fibers or a mixture ofboth. The fibers are usually held together with a binder and are coated,saturated, or otherwise impregnated with an asphaltic bituminousmaterial. The laminae lie one above another in the composite, and areexposed to view as a bulky composite when the shingle is installed on aroof. Inherent in this laminated construction is an appreciabledifference in surface elevation between the top surface of the tabs ofone shingle and the top surface of the tabs of the underlyingshingle(s). The perception of depth is greatly magnified when the arrayof shingles on the roof is viewed. The viewer's eye will naturally gofrom the deep wells formed by the adjoining tabs of one shingle to thoseof the next upper or lower shingle(s) and so forth over the roof.

A preferred laminate manifesting the inventive shingle's uniquestructure, incomparable to any of the prior art, comprises an asphaltshingle having a headlap portion and a butt portion which extends fromthe lower boundary of the headlap portion to the butt edge of theshingle and comprises a series of composite tabs which are separated byspaces, each extending from the side edge of one composite tab to thatof the next adjacent composite tab, and each of which comprises at leastthree layers. The type of laminated shingle consisting of a singleoverlay member and a single underlay tab is well-known and illustrated,for example, in U.S. Pat. Nos. 3,998,685 and 5,052,162.

In accordance with the process of the invention, one or more fibroussheets, which are to be made into the shingles, are treated with acementitious waterproofing composition, such as asphalt or otherbituminous material. The treatment includes surfacing the sheet orsheets with sufficient waterproofing material to which is adheredgranules such as crushed rock, slate or other surfacing material. Whilethe entire outer face of the shingle, i.e. the face which is uppermostwhen the shingle lies on a roof, is desirably covered over its fullextent with granular matter, the portion of the outer face which isimportant for colorful effects is that portion which is exposed to viewwhen the shingles are laid together in overlapping courses on a roof.Accordingly, the sheet portions which ultimately become these exposedportions are profitably surfaced with colorful granules so as to provideareas of distinctive coloration, and lower cost, less decorativegranular material is employed to surface the sheet portions which are tobecome the covered or hidden areas of the final assemblage.

The process is advantageously carried out continuously with the sheet(s)being transported along a production line for sequential processing. Thecontinuous process is especially useful in the production of laminatedshingles from a single elongate sheet. In the process, the top surfaceof the sheet is coated with asphalt and a coating of granules is appliedto this surface. At least two narrow elongate sheets or strips are cutfrom the total elongate sheet to yield a main sheet and the narrowportions cut therefrom. The narrow elongate sheets are desirably cutfrom the main sheet in one step, although the cuts may be made in morethan one step. The narrow sheets are positioned one above another andbelow the main sheet. A laminate of the main and narrow sheets isformed.

Desirably, each narrow sheet is coextensive with the other or others,and the narrow sheets are positioned so that the side edges of each oneare in the same vertical plane as the respective side edges of theother(s) lying above and/or below. The first narrow sheet moved directlybelow the main sheet is centered on the longitudinal line which willbecome the central line of the multi-layered portion of the totalcomposite sheet before cutting of this total sheet. Each succeedingnarrow sheet is centered on the narrow one above it. After centering,each cut-off sheet is adhered to the sheet above it to form a composite.Each cut-off sheet may or may not be inverted before adhesion. In theformation of an advantageous embodiment, the last adhered sheet isinverted. When the bottom sheet is thus inverted, the finalmulti-layered tab portion of the resultant roofing shingle has exposedgranules on both its top and bottom. The eventual shingle's butt edge isthickened by the multiple layers and their protruding granules, leadingto an assembly of the shingles on a roof which has the aestheticallyattractive, bulky look of a roof of wood or tile shingles.

A longitudinal cut is made along the centerline of and within the sideboundaries of the multi-layered portion of the totally laminatedcomposite sheet advancing along the production line so as to form twocomplementary sheets, each individually having multi-layered tabsseparated by cut-out portions along the thus cut longitudinal edge. Thecut defines a substantially zigzag or “dragons' teeth” configurationcomprising a series of interdigitated tabs on each complementary sheet.This side-edge arrangement is of the type described in U.S. Pat. No.5,052,162. Each resulting composite sheet is cut transversely intoshingles of preselected lengths. The zigzag cut desirably forms a seriesof tabs which differ from one another in each individual shingle so asto create a wooden shake simulation. The final shingle may thus be madefrom a single sheet, e.g., glass mat, by a process which converts thissheet into a plurality of shingles having multi-layered tabs, each layerbeing made of a portion of the original sheet. This multi-level roofingshingle is more visually appealing than previous bi-level shinglesbecause of its thicker butt edge. This look of thickness is especiallymanifest when the shingles are arrayed in rows on a roof and theshingles of each row act like levers lifting the butt edges of the rowabove and so forth over the entire roof.

An important aspect of the present invention is that it permitslaminated shingles having multi-layered tabs, such as those of threelayers, to be manufactured continuously and expeditiously from a singlesheet(s) of an indefinite length. Each of the steps involved in theformation of the final roofing shingles can be carried out on the baseroofing material (e.g., glass fiber mat) as the material advancescontinuously along the production line in the form of an elongate sheetand strips cut therefrom. The continuously performed steps comprisewaterproofing the sheet, coating it with mineral granules, cutting italong its length into elongate strips, laminating these strips togetherto form a composite multi-level strip, and finally cutting the compositelaminated strip into the individual roofing shingles. The granules maybe applied before or after the sheet is cut into elongate strips, asdescribed, for example, in U.S. Pat. No. 4,869,942, and may be appliedto only a portion of the main sheet or narrow strips. A differentcoloration may be applied to the main sheet and strips.

In a preferred embodiment of the invention, trilaminated shingles arecontinuously produced from a single elongate sheet which is waterproofedand coated over its top surface with mineral granules before being cutinto elongate strips. Two first straight cuts divide the sheet intothree elongate rectangular strips, one much wider than the other two.Advantageously, one of the straight cuts is made near one of the sideedges of the original elongate sheet, and the other straight cut is madenear the original sheet's opposite side edge. One of the two narrowstrips is shifted, without being inverted, to a position underneath thewide strip and the two strips are laminated together. Prior tolamination, the upper strip's undersurface which is to be bonded isadvantageously coated with an adhesive material. Additionally, inanother embodiment, the lower strip is turned upside down beforelamination so that the laminate of the two strips has the granules ofthe top strip facing upwardly and the granules of the bottom stripfacing downwardly. The second narrow strip is shifted underneath andlaminated to the bi-level portion formed in the first lamination.Preferably, the undersurface of the bi-level portion is coated with anadhesive and the second narrow strip is turned upside down beforelamination so that the total composite will have granules on both thetop and bottom of the three-layered, laminated section.

A third cut is made (i) alternately across and generally along thecenterline of the tri-level section (i.e., multi-layered portion) formedby the two previous laminations and (ii) within the longitudinal sideboundaries of this section. This central cut, which divides the sheetinto two elongate parts, is made to form a repeating pattern ofinterdigitating triply thick tabs so that upon separation each part hasa long straight edge along one side which is one layer in thickness andalternating triply layered tabs and cut-out portions along the otherside. Each of the narrow strips, which were positioned to underlie theuppermost wider strip, is desirably cut to be wide enough to completelycover the underside of the wider strip's tabs, but not so wide as toextend much toward the long straight edge of the wider strip. The widthis desirably sufficient to adequately support the overlying shingleportion and to contribute to ease of production in the continuousmanufacturing process. The two elongate laminated sheets are finally cutinto suitable lengths for shingles and packaged. This final cutting maybe accomplished conveniently just about when the third longitudinal cutis made or thereafter.

The continuous process thus provides a unique shingle structure havingalternating tabs, three layers in depth and cut-outs therebetween. Likeconventional bilaminates, this structure comprises a rectangular sheethaving headlaps and butt portions. When these prior art and inventivelaminated shingles are installed in successive offset courses inseparate arrangements on a roof, their butt edge portions are exposed toview. Because the inventive trilaminated shingle's butt portion is threelayers in depth, with the tabs and cut-outs three layers deep, theshingle presents, through this unusual enlargement of the butt portion,a bulky appearance that very closely approaches that presented by woodand tile shingles.

DESCRIPTION OF THE DRAWINGS

The invention will now be described with reference to the accompanyingdrawings in which:

FIGS. 1 and 3 are schematic elevational views of one form of apparatuswhereby laminated shingles may be manufactured according to thisinvention;

FIG. 2 is a top plan view of a sheet of fibrous material partiallycoated with granules in accordance with the invention;

FIG. 4 is a perspective view of the top and two bottom sheets laminatedtogether;

FIG. 5 is a perspective view of the novel roofing shingle of theinvention; and

FIG. 6 is a perspective view of an assembly of the shingles of theinvention as applied on a roof.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings and more specifically to FIGS. 1 and 3thereof, there is shown diagrammatically an overall process for formingmulti-layered roofing shingles according to the instant invention. Arectangular sheet or web 10 of an indefinite length is unwound from aroll (not shown) and fed along the production line. Sheet 10 ispreferably a mat of glass fibers but may also be fabricated from organicfelt or other types of base material. The glass mat is generally about38 to 48 inches in width, although other widths can be chosen withoutdeparting from the scope of the invention. The sheet generally weighsfrom about 1.35 to 3.00 lbs/100 ft.²

After sheet 10 is fed over a series of loopers 11-14 and between a pairof tension rollers 15 and 16 for uniform tensioning, it is then passedto a station for the application of filled asphalt coating. Dischargepipe 17 supplies a layer of the asphalt coating 18 to the upper surfaceof sheet 10 just before the nip of rotating rolls 19 and 20. Reservoir21 is placed below the coating area to capture runover asphalt from theoperation for application to the sheet by back coating roll 20 immersedin the asphalt of reservoir 21. Nip rolls 19 and 20 coact to apply theappropriate weight of asphalt coating to the sheet, with the nip of therolls providing pressure to ensure that the asphalt has impregnated thesheet properly. Heating units 22 keep the coating asphalt at the propertemperature for application.

Downstream of roll 20 is another back coating roll 23, which is alsoimmersed in reservoir 21 for pickup of liquid asphalt and deposition onthe back surface of sheet 10. Sheet 10 may be coated by both rolls, asshown in FIG. 1, or it may be subjected to a single treatment by one orthe other of the rolls. Excess asphalt is advantageously wiped from thesurface of the back coating roll(s) by a doctor knife(s) 24 or the like,installed on either or both sides of the back coating roll(s) to ensureuniform application and avoid excesses of the asphalt. Downstream of theback coating application there is a doctor blade or knife 25 or the likewhich removes excess coating from the back or under surface of sheet 10.Sheet 10 is further acted upon by a smoothing roll 26 and a carrier roll27, which rolls are generally heated.

Stabilized asphalt coating 18 suitably has a softening point as measuredby ASTM D36 of from about 195° to 260° F., more preferably from about215° to 235° F., and is usually applied in an amount from about 50 to 70pounds, more preferably from about 55 to 65 pounds, per 100 square feetof sheet 10. The coating is advantageously maintained at about 380° to450° F. before application to the sheet.

After the coating step and while the coating material is still hot, softand tacky, coated sheet 10 passes beneath surfacing apparatus 28 fromwhich decorative granules are deposited on the upper surface of thesheet. Apparatus 28 includes a series of bins filled with mineralgranules and positioned above the longitudinally moving sheet. Thisknown type of roofing machinery is equipped for selectively depositingthe mineral granules contained in the bins onto the adhesive uppersurface of sheet 10. Apparatus 28 is outfitted with enough bins to holdeach collection of granules to be applied to the sheet in the formationof the overall color pattern being developed on the sheet.

In the mineral granule treatment schematically shown in FIG. 2, sheet 10is moving longitudinally under apparatus 28 in the direction of thearrow. The granule deposition can be understood with reference to thelines extending longitudinally and transversely over the surface ofsheet section 29, as shown in FIG. 2. The three solid lines runninglongitudinally between the two side edges of the sheet correspond to thecuts to be subsequently made in the formation of the component laminaeof the shingle, as set forth below. It is seen that there will be twostraight cuts and one zigzagged cut. The cutting pattern of FIG. 2 ismerely one of many such patterns which could be used to produce thecomponent laminae. The two dashed lines extending lengthwise to eitherside of the zigzagged line do not correspond to eventual cuts but, inconjunction with the other four straight and parallel lines extendinglengthwise, including the side edges, demarcate five zones which aredesignated zones A-E. As indicated in FIG. 2, the widths of the zonesacross sheet 10 are as follows: zones A and E-7″; zones B and D-5″; andzone C-14″. These five zones extend over the entire length of sheet 10.The overall width of sheet 10 as well as the number and widths of thezones can vary depending on factors such as the capacity of theapparatus and the number and size of the shingles being produced perunit length of the sheet.

The granule discharges which are applied onto the five zones of section29 are made from the above-mentioned bins of apparatus 28. The bins arecontained in two applicator compartments, a so-called blend box 30 andspill box 31. In progressing along the production line, sheet 10 firstpasses under applicator box 30 which deposits granules onto zone C, andthen under applicator 31, which deposits granules onto all of the zones.As shown in FIG. 2, the far right side of section 29 of sheet 10 haspassed under both applicator boxes 30 and 31 and thus has granulescovering all of the zones, while the left-hand side, having passed underonly applicator box 30, has the granules covering only zone C. As sheet10 progresses further along the production line, the uncovered zones ofsection 29 will, of course, become covered by granules discharged fromapplicator box 31.

In a preferred embodiment of the invention, the roof's exposed layersfrom zone C are in the form of an effectively random series ofdifferently colored portions. To form this random pattern in zone C,applicator (blend) box 30 is equipped with a group of bins, each ofwhich contains variously colored granules for application to zone C. Thecontents of each bin advantageously consist of blends of the coloredgranules. The deposition of blends is found to protect against thesurface flaws encounterable with the use of singly colored granules.There must be a sufficient number of these bins to produce a random lookon the covered roof surface. Suitably, there are at least four such binseach holding different color blends of mineral granules. Applicator box30 of FIG. 1 has four such bins from which the blends of the containedmineral granules are selectively dropped onto the upper surface of sheet10 as it passes beneath these bins. The average of the colored granulesfound in these four bins is contained in a bin of applicator box 31 forthe follow-up treatment of zone C described below. This average orcomposite of all the colored granules not only adds an aestheticallypleasing color variation but also permits the utilization of theinevitable accumulation of the spilled granules from the other bins.

The selective dropping of mineral granules from the bins of applicatorbox 30 results in deposited bands of mineral granules (so-called “colordrops”) on zone C. The first four such bands of FIG. 2, which aredesignated C1 through C4, are bordered by dotted lines L extendingacross zone C. The deposition from applicator box 30 is interrupted atvarious randomly located places along zone C, yielding spaces designatedS, which are uncovered by granules.

After its passage under applicator box 30, sheet 10 next passes underapplicator (spill) box 31, which is divided into a number of binssupplied with granular material and equipped for the simultaneousapplication of the granules across sheet 10 to complete the coverage ofzones A to E. One of these bins continuously delivers to zone C a blendof colored granules which represent the average of the granulesdeposited from the four bins of applicator box 30. The spaces designatedS of zone C become covered with this average blend. Additionally,granules of this blend fill in any spots left uncovered in bands C1 toC4 after the surfacing by applicator box 30.

Applicator boxes 30 and 31 thus together provide on zone C a series ofcolor drops or bands C1 through C4 and S, each band having a variablelength and a color which contrasts with the color of the mineralgranules in the bands adjacent thereto in the completely granule-coveredsheet. In the embodiment illustrated in FIG. 2, each of the color dropsonto each of zones C1, C2, C3 and C4 (bounded by a pair of dotted lines)is about 11 inches lengthwise along sheet 10. Applicator boxes 30 and 31are operated to alternate the color drops from the five mineral granulebins in an effectively random fashion. The term “effectively randomfashion” is used since the machinery is constructed to set up a patternof alternating color drops which for the FIG. 2 embodiment is repeatedonly after 36 such color drops. This 36 drop cycle results in a patternof such color drops which, for practical purposes in the final roofcovering of the invention, is undetectable visually from an entirelyrandom, nonrepeating pattern.

As shown in FIG. 2, the first six designated color blends or bands fromthe five granule-containing bins of applicator boxes 30 and 31discharging onto sheet 10 are C1, S, C2, S, C3 and C4 in order fromright to left. Color drop S., which constitutes the average color blendwhich would result from a combination of the colored granules of dropsC1, C2, C3 and C4, is applied twice from its bin in this group of sixdrops. As sheet 10 advances, applicator boxes 30 and 31 apply this samegroup of six color blends, viz. C1 to C4 and S, (deposited twice), as aset over and over to zone C but with the sequence of the six dropschanged from each set to the next. After the application of sixdifferently ordered sets or a total of thirty-six color drops, the cycleof these six sets is repeated on and on over the entire length of sheet10. The result of this coloring process is an effectively random,nonrepeating color pattern on the shingles' overlying laminae derivedfrom zone C.

Applicator box 31 is further equipped with one or more bins forapplication, simultaneously with the application of the continuouslayers of granules to zone C of continuous layers of granules to zonesA, B, D and E. As will hereinafter be understood, the material of thelatter four zones form portions which are not visible in the completelyconstructed and installed shingles of the invention. Accordingly, thegranules deposited on these four zones suitably are low cost materials.

As illustrated in FIG. 1, after the stream of granules is dischargedfrom applicator box 31 onto sheet 10, the sheet goes around a slate drum32 which functions to embed the granular material in the top asphaltcoating. In the continued passage of the surfaced sheet 10, excessgranules fall off from the sheet into applicator box 31 from which theyare reapplied onto the sheet. The back of the sheet then comes underhopper 33 containing fine back-surfacing material, such as talc, micadust, fine grit, sand or other composition capable of rendering the backof the sheet non-cementitious. The material from hopper 33 is uniformlydistributed over the back of the sheet by means of a distributing roll34. The coated roof sheet at this point generally weighs from about80-100 lbs/100 ft.²

Sheet 10 next passes through a cooling section 35 which may simplyinvolve a water spray or a series of cooling rolls 36 around which sheet10 is looped. At the finish looper station 37, the sheet is fed over aseries of rolls 38 which control its speed as it advances to theslitting station (see FIG. 3). After embedment of the granular materialon sheet 10 by slate drum 32 and prior to slitting of the sheet,adhesive strips (not shown) are desirably applied to the front or backof the sheet. In the final roof covering, this adhesive material acts asa self-sealing means for attaching the shingles in one horizontal courseto those in the next upper or lower course. At this interval duringshingle production, release tape (also not shown) should be affixed tothose sheet portions which in the finished and packaged shingles willcome in contact with the above-mentioned adhesive strips of adjacentshingles. Sticking in the package is thereby prevented.

As shown at the right-hand side of FIG. 3, the cooled sheet is pulled byrolls 40 and 41 and divided lengthwise at a slitting station 39,utilizing two cutters, into three portions, a wide sheet 10 a and twonarrow sheets 10 b and 10 d. The cutting may be accomplished by anysuitable means, such as by cutting wheels. More than two cutting wheelscould be utilized for the production of shingles having four or morelayered tabs. Advantageously, the original 38 inch wide sheet of thepreferred embodiment of FIG. 2 is cut along the lines separating zones Aand E from the remainder of sheet 10 or more specifically from zones Bthrough D. Accordingly, for this embodiment, slitting station 39 cutssheet 10 into a sheet 10 a (zones B through D) which is 24 inches wideand two sheets 10 b (zone A) and 10 d (zone E) which are each 7 incheswide. At this point both the main sheet 10 a and the narrow strips 10 band 10 d have granules embedded on their upper surfaces.

Sheets 10 a and 10 b are pulled and guided along by conventional rollers42-44. The wide sheet 10 a is fed over a back coater 45 which comprisesa tray 46 containing adhesive, such as asphalt, and a drum 47, whoselower surface rotates in the adhesive-containing tray 46. Drum 47applies adhesive from the tray to the back side of zone C of the widesheet 10 a to form an adhesive coating zone about the width of thenarrow strip 10 b (zone A) or 10 d (zone E), e.g., about 7 inches wide,to receive strip 10 b. The adhesive may be applied as a continuous layeror as strips.

Strip 10 b passes up over a guide bar 48 and then across to anotherguide bar 49. In its passage from guide bar 48 to guide bar 49, strip 10b is shifted underneath strip 10 a so that the centerline of thenarrower strip is below and coincident with the centerline of zone C ofthe wider strip. With their centerlines so aligned and theirgranule-covered surfaces both facing upwardly, the two strips arebrought into contact and strip 10 b is pressed against theadhesive-coated underside of main strip 10 a by laminating rolls 50 toform a composite 10 c of the two strips. In a further embodiment of theinvention, strip 10 b is twisted in its passage from guide bar 48 toguide bar 49 so that its bottom without granules faces upwardly forbonding to the back side of strip 10 a. This results in the formation ofa laminated composite of the two strips having one layer of granulessurfacing the composite's upper surface and another layer of granulessurfacing the lower surface of strip 10 b.

Trilaminate 10 e of the invention is formed by essentially repeating theprocess carried out in forming bilaminate 10 c, as shown in FIG. 3. Thewide sheet composite 10 c is fed over a back coater 45′ comprising anadhesive-containing tray 46′ and a drum 47′. Drum 47′ applies theadhesive, e.g., asphalt, to the downwardly facing, backside surface ofstrip 10 b (original zone A) which constitutes the lower surface of thelaminated portion of sheet 10 c.

Strip 10 d passes up over a guide bar 48′ and then across to anotherguide bar 49′. In its passage from guide bar 48′ to guide bar 49′, strip10 d is twisted so that it is turned upside down (180°) and its backwithout granules faces upwardly for bonding to the laminated portion ofthe backside of strip 10 c. Strip 10 d is then shifted underneath strip10 c so that the centerline of the narrower strip is below andcoincident with the centerline of the wider strip 10 c. With theircenterlines so aligned, the two strips are brought into contact and theasphalt coated underside of strip 10 c is pressed against the top side(originally bottom side) of narrow strip 10 d by laminating rolls 50′ toform a composite. 10 e of the two strips having one layer of granulessurfacing the composite's upper surface and another layer of granulessurfacing the lower surface of strip 10 d. By instead again carrying outthe embodiment involving not twisting the lower laminae, a trilaminatewill result with granules on the composite's upper surface and the uppersurface of each lower layer.

As shown in FIG. 3, laminated combination 10 e is fed into a cuttingstation 51 which is equipped to make one lengthwise cut along thislaminate. The cutter suitably comprises a lower cutting wheel and anupper anvil roll. The path of the lengthwise cut is illustrated in FIG.4. While it is not illustrated in FIG. 4, cutting station 51 alsoprofitably makes transverse cuts in laminate 10 e to form the individualinventive shingles, one of which is shown in FIG. 5. In FIG. 4, thecenterlines of strips 10 b and 10 d are shown aligned with thecenterline of main sheet 10 a and the lengthwise cut performed atcutting station 51 is shown as an angularly offset line forming tabs 52and 52′. The cut separates the laminated sheet 10 e into two lengthwiseparts 10 f and 10 g, which comprise two complementary, interlocking-tabstrips, each of which is cut transversely of its length into shingles ofthe desired length by transverse cutters or any other suitable cuttingmechanism. An appropriate length F for each shingle is 40 inches, asshown in FIG. 2 for two portions of sheet section 29. In a preferredembodiment, all shingles cut from strip 10 f have the same shape and allthose cut from strip 10 g have the same shape, and the average surfacearea of all the shingles cut from strip 10 f is the same orapproximately the same as that of all the shingles cut from strip 10 g.

With reference to zones A to E of sheet 10 shown in FIG. 2, it is seenthat the topmost layers of strips 10 f and 10 g are derived from zonesB, C and D, and the underlying layers are derived from zones A and E.Each of strips 10 f and 10 g has tabs which are three layers thickbecause of the previous laminations of zones A and E underneath thecentral portion of zones B, C and D. Advantageously, strips 10 f and 10g are each 12 inches wide or greater. The resulting shingles areconveyed for packaging to stations 53 and 53′.

FIG. 5 shows a perspective view of a final shingle 54 with an upper mainsheet 55 having granules 56 on top and two strips 57, 57′ adhered alongthe angularly shaped edge thereof. Strip 57′ has exposed granules on itsside facing downwardly. As shown in FIG. 5, shingle 54 comprises aheadlap portion 58, which is approximately rectangular in shape, and abutt portion 59, which is divided into the series of spaced-apart tabs52 which are integral with and extend from the headlap portion 58. Alower longitudinal section of headlap 58 is seen to form part of the toplayer of the tri-level portion of shingle 54. The tabs 52 are spacedapart from each other at a distance which will ensure that aconsiderable portion of an underlying tab(s) will be viewable when anarray of the shingles is installed on a roof. The spacing between thetabs may vary and is preferably greater than two inches and morepreferably is greater than 2½ inches, such as from about 3 to 7 inches.The tabs 52 may be of equal and/or unequal widths and each widthtypically is in the same range as that of the spaces therebetween. Thetabs may have various shapes.

FIG. 6 illustrates a roof covered with a plurality of successive offsetcourses of laminated shingles 54. The triply thick marginal edge of thebutt portion of each shingle of a given course abuts the likewise triplythick marginal edge of the adjacent shingle of that course. Furthermore,as illustrated in FIG. 6, the shingles of a course 60 are offset fromthe shingles of an immediately subjacent course 61 by a firstlongitudinal distance and the shingles of course 61 are, in turn, offsetfrom the shingles of the next immediately subjacent course 62 by asecond longitudinal distance, the first and second longitudinaldistances desirably being unequal to each other. The longitudinaldistances may be equal and/or unequal over the entire surface of theroof.

The respective courses of shingles of the FIG. 5 embodiment may beoffset from each other at any distance less than the length of a shingleand such distance may be varied at random without adversely affectingthe appearance of the ultimate roof covering. Contrarily, thearrangement of the inventive shingles on a roof produces an appealinglyvariegated look with strikingly deep wells throughout the extent of theroof. As is evident in FIG. 6, a view of the exposed lower edges of thebutt portions of shingles of one course in conjunction with the directlylower exposed butt edges of the shingles of a successive course revealsthicknesses which are three times (see 63) and six times (see 64)greater than the thickness of the granule-covered sheet material fromwhich the shingles are made.

1. A laminated roofing shingle comprising a headlap portion and a buttportion, the butt portion comprising a series of multi-layered tabs, allthe multi-layered tabs having the same number of layers and eachmulti-layered tab (a) being separated from the next adjacentmulti-layered tab or tabs by a space or spaces, respectively, and (b)comprising an upper most layer and at least two layers underlying theuppermost layer, each underlying layer being laminated to the layerabove it to form a multi-layered laminated composite, the laminatedcomposite being integral with the headlap portion and the top surface ofthe uppermost layer of each tab being coplanar with the top surface ofthe headlap portion.
 2. A roof covering comprising a plurality ofsuccessive courses of laminated shingles, the shingles of each coursebeing laid side-by-side, each course being offset from the adjacentcourse or courses by a distance less than the length of any shingle, andeach shingle comprising a headlap portion and a butt portion, the buttportion comprising a series of multi-layered tabs, all the multi-layeredtabs having the same number of layers and each multi-layered tab (a)being separated from the next adjacent multi-layered tab or tabs by aspace or spaces, respectively, and (b) comprising an uppermost layer andat least two layers underlying the uppermost layer, each underlyinglayer being laminated to the layer above it to form a multi-layeredlaminated composite, the laminated composite being integral with theheadlap portion and the top surface of the uppermost layer of each tabbeing coplanar with the top surface of the headlap portion.
 3. Alaminated roofing shingle comprising a headlap portion and a buttportion, the butt portion comprising a series that is a plurality ofstacked multi-layered spaced-apart tabs, each tab layer comprising afibrous sheet impregnated with a bituminous material and having acoating of granules on a surface thereof, all the multi-layered tabshaving the same number of layers and each multi-layered tab (a) beingseparated from the next adjacent multi-layered tab or tabs by a space orspaces, respectively, and (b) comprising an uppermost layer and at leastanother layer underlying the uppermost layer, said underlying layerbeing laminated to the layer above it to form a multi-layered laminatedcomposite, the laminated composite being integral with the headlapportion and the top surface of the uppermost layer of each tab beingcoplanar with the top surface of the headlap portion.
 4. A roof coveringcomprising a plurality of successive courses of laminated shingles, theshingles of each course being laid side-by-side, each course beingoffset from the adjacent course or courses by a distance less than thelength of any shingle, and each shingle comprising a headlap portion anda butt portion, the butt portion comprising a series that is a pluralityof stacked multi-layered spaced-apart tabs, each tab layer comprising afibrous sheet impregnated with a bituminous material and having acoating of granules on a surface thereof, all the multi-layered tabshaving the same number of layers and each multi-layered tab (a) beingseparated from the next adjacent multi-layered tab or tabs by a space orspaces, respectively, and (b) comprising an uppermost layer and at leastanother layer underlying the uppermost layer, said underlying layerbeing laminated to the layer above it to form a multi-layered laminatedcomposite, the laminated composite being integral with the headlapportion and the top surface of the uppermost layer of each tab beingcoplanar with the top surface of the headlap portion.
 5. A roofingshingle comprising a top asphalt coated layer, a second asphalt coatedlayer, adhesive means between said layers to secure said layers togetherto form a two-layered, laminated roofing shingle, said second layerbeing equal in length to said top layer but being substantially narrowerthan said top layer and having one edge of said second layer inalignment with one edge of said top layer, with all laminated layers ofsaid shingle having spaced-apart alternating tabs and cut-out portions,throughout said layers, along one edge thereof, said top layer and saidsecond layer having particles embedded on opposite facing sides of saidroofing shingle.
 6. A roof covering comprising a plurality of successivecourses of laminated shingles, the shingles of each course being laidside-by-side, each course being offset from the adjacent course orcourses by a distance less than the length of any shingle, and eachshingle comprising a top asphalt coated layer, a second asphalt coatedlayer, adhesive means between said layers to secure said layers togetherto form a two-layered, laminated roofing shingle, said second layerbeing equal in length to said top layer but being substantially narrowerthan said top layer and having one edge of said second layer inalignment with one edge of said top layer, with all laminated layers ofsaid shingle having spaced-apart alternating tabs and cut-out portions,throughout said layers along one edge thereof, said top layer and saidsecond layer having particles embedded on opposite facing sides of saidroofing shingle.